(1) Field of the Invention
The subject invention relates to the antistatic resinous compositions having permanent antistatic performances, the superior mechanical properties represented by impact strength and flexural modulus, and high flowability.
(2) Description of the Prior Art
Thermoplastic resins are extensively used because of their superior characteristics. However, they generally cause various troubles due to static electricity because of their high electric resistances.
Mixing antistatic agents such as water absorbing compounds and surfactants therein and applying them to the surface of the moldings thereof are generally used among the methods for giving antistatic performance thereto. The methods, however, are problematic in that antistatic performance disappears through surface wipe-off and water wash and mixed components bleed out at the surface to deteriorate their quality as the materials.
Proposed methods for giving permanent antistatic performance to thermoplastic resins include the partial copolymerization of hydrophilec monomers such as acrylamide, methacrylamide, polyethyleneglycol acrylate, polyethyleneglycol methacrylate and sodium p-styrene-sulfonate in polymerizing the impact resistant resins represented by acrylonitrile-butadiene-styrene graft terpolymer(ABS) for example (Published Unexamined Japanese Patent Application No. 98317/1983).
Therein, however, the copolymerization quantity of hydrophilic monomers is limited, because they considerably deteriorate in mechanical peoperties such as flexural modulus and impact strength, in flowability and in the resestance to hot water and alcohol, when copolymerized with in great quantities. So, it is difficult to attain sufficient antistatic performance.
Proposed besides is mixing in thermoplastic resins the graft copolymers obtained by graft copolymerizing the hydrophilic rubber polymers with vinyl or vinyliden monomers; the former have been copolymerized conjugate diene or/and acrylate ester and the vinyl monomers having an alkylene oxide radical, or mixing in thermoplastic resins the hydrophilic rubber polymers obtained by copolymerizing conjugate diene or/and acrylate ester, the vinyl monomers having an alkylene oxide radical and unsaturated carboxylic acid monomers (Published Unexamined Japanese Patent Application No. 36237/1980).
They are, however, defective in that their manufacturing processes are complicated because the rabber polymers used are special types and obtained resin compositions have inferior mechanical properties because of those of the rubber polymers.